Problem: The Bert Crane Wastewater Treatment Plant in Atwater, California, needed an effective, low-maintenance aeration solution for its two aerobic digesters. Traditional blowers and diffusers posed challenges including high energy usage, clogging and costly maintenance that required entering the tanks. The facility, operated by Veolia, sought a solution that could meet stringent California discharge regulations while simplifying operations and improving biosolids quality.
Solution: Mazzei Injector Company provided a blowerless, diffuser-free aeration system using venturi injectors. Each digester was equipped with six 12-inch injectors connected to chopper pumps that recirculate basin water through the injectors. As water flows through the venturi, a vacuum draws in atmospheric air, creating a fine air-water mixture. This mixture is reintroduced to the digester via mixing nozzles, delivering oxygen efficiently to boost microbial activity and reduce volatile solids. The design handles high solids without clogging and requires no in-tank aeration components.
Result: The system delivered reliable oxygenation with minimal maintenance. Noise was significantly reduced, and efficient mixing helped prevent solids buildup, reducing cleaning time. The digested material is dewatered using screw presses to produce Class B biosolids, with the ability to store for 90 days to achieve Class A status. 661-363-6500; www.mazzei.net
